The Quadros are slightly more different in that they can output higher-bit colors. Up to 12-bit on the new C-class.

These, however, are basically Quadros without the extra graphics features, and with several Cuda optimizations.

You see, thats the thing though, the Quadros often have a few features over the regular GeForce's(Ram, optimized hardware, driver tweaks, etc) that have proven them a must have, regardless of their mark up, for studios.

I'm not quite convinced with the Tesla, that those few optimizations are a "must have" as opposed to a regular GeForce with CUDA enabled. I guess what I'm trying to say is that while the Tesla may be worth it to a few development houses out there, its yet to be proven that its "worth" the extra cost, as with any new product I guess.